Walpole Reservoir Dam

MAD BROOK· Cheshire, New Hampshire· Built 1901· Earth· 20 ft tall
High Hazard Water Supply Local Government

Key Takeaway

Walpole Reservoir Dam is classified as high hazard in New Hampshire. It was completed in 1901 and is 125 years old. Its primary use is water supply. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 20 ft (taller than 70.9% in NH)
Dam Length355 ft
Dam TypeEarth
Max Storage16 acre-ft
Normal Storage5 acre-ft
Surface Area3 acres
Drainage Area1 sq mi
Max Discharge642 cfs
Year Completed1901 (125 years old)
Year Modified2003
NID IDNH01100

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: September 23, 2021
State Regulated: Yes
Regulatory Agency: NH DES

Ownership

TOWN OF WALPOLE

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Walpole Reservoir Dam?

Walpole Reservoir Dam is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Walpole Reservoir Dam?

Walpole Reservoir Dam is owned by TOWN OF WALPOLE (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Walpole Reservoir Dam built?

Walpole Reservoir Dam was completed in 1901, making it 125 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Walpole Reservoir Dam?

Walpole Reservoir Dam serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Walpole Reservoir Dam?

Walpole Reservoir Dam has a dam height of 20 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Walpole Reservoir Dam last inspected?

Walpole Reservoir Dam was last inspected on September 23, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.